A typical electrochemical cell may include a cathode side and anode side separated by a separator arrangement. The cathode side may include a cathode current collector, a cathode electroactive material (reduced on discharge) and an electrolyte. The anode side may include an anode current collector, an anode electroactive material (oxidized on discharge) and an electrolyte. The separator arrangement separating the cathode and anode sides, inter alia, permits ionic flow therebetween. The current collectors, electroactive materials, electrolytes and separator arrangement thus form an electrochemical reactor that converts chemical energy to electricity. Hence, the current collectors may be (externally) electrically connected together to form an electrical circuit.
In this context, the electrochemical reactor is an electrochemical cell within which the cathode electroactive material and anode electroactive material do not flow into and/or out of the electrochemical reactor during operation: they are fixed.